1. Description of the Prior Art
Airless blast cleaning devices have been well known for a considerable period of time. Blast cleaning devices have been manufactured and sold by Wheelabrator-Frye, Inc., 400 South Byrkit Avenue, Mishawaka, Ind. 46544, for a number of years and are described in U.S. Pat. No. 2,708,814, for example, which relate to an airless blast cleaning device utilizing centrifugally thrown abrasives to clean parts by a blast cleaning method.
In existing blast cleaning devices, the Protective housing employs a plurality of replaceable liner elements which serve to redirect the stream of abrasive from the centrifugal wheel to the particular workpiece. In prior art devices, some 21 individual liner elements were required and, even in refinements of that device, some nine replaceable elements were required. Replacement of liner elements is both an expensive and time-consuming procedure and requires substantially complete disassembly of the blast cleaning apparatus.
Additionally, existing blast cleaning devices using centrifugal wheels and replaceable blades require replacement of the blades from time to time. In existing devices, the blades are replaced from the outer edge of the supporting disk and require removal of the existing blade, insertion of a new blade and then the fitting of a specific spring holding device to secure the blade from movement relative to the disk to centrifugal force as the disk is rotated. The specific structure of the prior art wheels require the use of a single size blade with a particular wheel and does not permit freely substituting varying size blades on a common set of disks to provide blast cleaning devices having different characteristics mountable in a common housing assembly.
2. Field or the Invention
This invention relates to cleaning of workpieces utilizing airless blasting techniques. More particularly, this invention relates to apparatus for housing an airless blasting wheel which permits use of a direct drive DC motor to rotate the blasting wheel and which permits easy access to the blasting wheel by removal of a single access plate. Additionally, this invention relates to wheel apparatus capable of accepting varying length blades to provide cleaning devices having differing characteristics utilizing common wheels and housings.